Project Summary Biological sex and nutritional status influence immune function, and the proposed research in this supplement seeks to understand the relationships between sex, nutrition, and immune response in the context of dengue virus infection. Nutritional deficiencies and dengue illness contribute substantially to the burden of disease in resource limited settings. The proposed research will address gaps in how biological sex and nutritional status relate to dengue immunopathology. Our goal is to better understand the role of sex and nutritional factors in differential disease risk, vulnerability, and outcome with an ultimate goal of advancing scientific knowledge about women?s health. As part of a parent R01 award, we are collecting detailed information on demographics and health status, anthropometry measures, and blood specimens from 300 consenting pediatric participants who present to hospital with symptoms of acute febrile illness. Participants attend acute and convalescent study visits, and confirmatory dengue diagnostics is included in the parent study. The supplement research proposes to measure a comprehensive panel of nutritional and immune response biomarkers in stored serum specimens of confirmed dengue participants and analyze the resulting data for associations stratified by sex. By conducting basic and translational research on sex differences in the pathobiology, prevention, and treatment of dengue, we aim to inform both clinical care and public health programs for best practices that account for men and women in any setting. In addition, this work will also inform the design and development of our personalized diagnostics platform, the focus of the parent R01 award.